Fluid operated propeller pitch controlling mechanism



July 4, 1950 E. ATTESLANDER 2,513,546

FLUID OPERATED PROPELLER PITCH CONTROLLING MECHANISM gw m 2 1 ATTORNEYS-V m 0 N g i TE 7 0 7 6 7 W m Z 6 w 00 my a 6 7m .v 0 6 I17 J i W 6 =4 66 f m M 9 W 1 T w, 6 w R, in g 5 2 W A, 0 2 m. 6 N ,6 J 6 M 3 d n f e p 1 6 m m 6 m 6 w o 4 6 6 6 6 w w 6 MW w 6 6 W Patented July 4, 1950 FLUID OPERATED PROPELLER PITCH CONTROLLING MECHANISM Edouard Atteslander, Winterthur, Switzerland, assignor to Sulzer Freres, Societe Anonyme, Winterthur, Switzerland Application September 12, 1945, Serial No. 615,718

UNITED STATES PATENTOFFICE In Switzerland December 2, 1944 5 Claims.

In order to eliminate this disadvantage the present invention provides a servomotor for adjusting propeller blades during service which, while turning with the propeller shaft and operated by pressure medium, is arranged in an enclosed stationary casing sealed at the outlet opening for the propeller shaft.

An embodiment of the invention is shown dia grammatically in the drawing.

Fig.1 shows a longitudinal section through 20 Fig. 2 a cross-section on the line IL-II of the casing surrounding the servomotor.

Fig. 1,

Fig. 3 a longitudinal section through the servomotor and the control members to a larger'scale.

In the shafting of a propeller which serves for the;propu1si0n of .a water or air craft the servomotor I is inserted between the intermediate shaft 2, which is connected to the propulsionplant, and the propeller shaft -3. Attached to the latter is the propeller, not shown, with blades adjustable in service. The servomotor I is supported in the bearing shells 4 and 5 connected to the casing bottom 6 and the upper part 1 of the casing, which are closed by the cover 8.

The upper bearing shell 5 carries the control casing 9 with the control valve I of the servomotor I and the small receiver piston ll of the scaling is provided by the stufiing-boxes l3 and M. The pressure medium for the servomotor I,

usually pressure oil, is supplied and led off through L the connecting branches i and IS, the passages l1 and I8 in the control casing 9 and in the upper bearing shell 5, according to the position of the control valve l0, and further through the annular grooves l9 and in the bearing shell 4 and 5, passing from there through the passages 2| and 22 to the servomotor pistons in the casing of the servomotor l.

The leakage oil from the bearing 4, 5 of the er om tor l c ects in the um: 23, is drawn oil in through the suction pipe 21 by the pump 24, which is designed for instance as a gear-type pump and driven through the helical gear wheels 25, 26 from the intermediate shaft 2, and is delivered through the pipe 28 into a container not shown in the drawing. A drain pipe down to a lower container might also be connected to the sump 23 in place of the pump 24.

In this way the servomotor casing 58 is unable to fill with pressure medium and cannot be loaded by the pressure of the pressure medium. Consequently the stuffing-boxes l3 and M are also relieved of all pressure and losses of pressure medium are practically impossible. Stuffing-boxes on the propeller shaft subjected to v the pressure of the pressure medium are thus entirely dispensed with. The control parts are also completely protected against dirt, rust and damage.

In order to keep the sealing of the bearing 4. 5 intact if possible for years, wear is practically prevented by the weight of the casing 6-8, of the bearing 4, 5 and of the control parts 9 and [0 being entirely compensated. The springs 29, 30, which are mounted between the projecting pieces 3| on the casing element 6 and the foundation 32, are provided for this purpose. A pair of springs 29, 30 may be provided in one or two cross-sections of the casing 6-8. When there is only one pair of springs 29, 30, this is arranged in the plane in which lies the centre of gravity of the casing.

In order to prevent the casing from turning the pins 33, 34 are provided, and these can be adjusted, with a small clearance required for the spring efiect, by means of the nuts 35. The loading of the springs 29, 30 can be accurately adjusted with the nuts 36. The servomotor I may have one or more pistons which move along the axis of the propeller shaft or are designed as rotary pistons. In both cases the adjusting member 48 in the shaft 3 can perform either a rotary movement or a longitudinal movement in the propeller shaft 3 to adjust the blades of the propeller.

Between reciprocating pistons and. a rotary adjusting shaft 48 a worm gear with steep thread is arranged in a known manner. The adjusting linkage in the hub of the propeller between the member 48 and the propeller blades is designed in a known manner according to the movement of the adjusting member 48. The servomotor i Fig. 3.

In the servomotor l are the pistons 46 and 41, which are mounted on the adjusting rod 48 and supported against each other and against the fixing screw by the distance sleeves 49 and 5! The pistons 46 and 47 run in liners 52 and 53 and are shut off and fixed by the cover 54 and the screwed'sleeve 55. The liner 53 is integral with the partition 56.

The servomotor cylinder I rotates in the two piece bearing with the lower shell .4 and the upper shell 5, which are held together by the bolts 51, Fig. 2. The control member ii) works in the bore 58 in collaboration with the pressure medium turns the valve Ill towards the closed position supply l5 to the space 59 and the pressure medium discharge it from the space 60, as do also the passages H and I8 leading to the servomotor" l, which are covered by the control edges 51 and 62 in the closed position of the control valve Ill.

The passage I1 is in communication with the annular groove IS in the bearing 4, 5. The passage IB is in communication with the annular groove 2%. From the annular groove I 9 the pressure medium passes through the passage 2 I, the groove 63 in the liner 52 and the openings in the liners '52, 53 leading to the piston spaces to the 5 left of the pistons '46 and 41, while the annular groove communicates with the passage 22, to which is connected the groove 64 in the liner 52. From the groove 54 the pressure medium passes into the piston spaces lying to the right of the pistons 46, ll.

In a further bore in the casing '9 is the small piston l I, which acts as'a receiver in the hydraulic system l2 and adjusts through the set screw 65 the slide piece 65 and the lever 67 in opposition to the force of the spring 58, the loading of which can be altered "by means "of the set screw 69. The lever 61 is connected through the link 18 to the control member If; and through the link H to the segment-shaped slide piece 12, which is fitted in the groove '33 of the adjusting disc T4. The adjusting disc M is rigidly connected through the rods 15, which are screwed into the disc 76, to the pistons lfi, W and the adjusting rod 48.

' The linkage 72 to 75 forms the return 'mec'ha nism of the control member Ill through the servomotor pistons 16, ll. The rods 15 are passed through the flange of the intermediate shaft 2; continuous slots in the driving shafts 2, 3- for returning the movement of the linkage '43 in the interior of the propeller shaft 3 to the control member outside of this shaft can be avoided by this means to some advantage, since such slots represent a considerable weakening of the propeller shaft.

The device works as follows: if an adjustment of the propeller blades is started in the hydraulic system I2 by a change of pressure, for instance a pressure rise, acting through the transmitter not shown in the drawing but provided at the controls, the small piston H moves to the left. The slide piece 66 turns the lever 61, the valve I Ois then moved to the left out of the closed position shown, so that pressure medium from the pipe [5 enters the passage H and the annular groove l9, passes through the passage 2! and the groove 63 to the left of the pistons 46, '4'? into the servomotor cylinder, where it moves the pistons 46, 4'! with the adjusting rod 48 to the right and brings about a turning of the propeller blades, for instance from the position for full speed ahead towards the neutral position. In the neutral position of the blades, in which the propeller exerts no thrust whatever, the pistons.

46, 41 are in the middle position; the outerrnos't 7 said passages, said sleeve being inside said casing shown. When the small piston H is brought to a standstill, the valve Hi will be moved to the right till the passages 51 and [8 are completely closed and will remain in this closed position. The pistons '45, M moving to the right force the pressure medium in the right-hand piston spaces through the groove Ki l, the passage 22, the annular groove 28 and the passage [8 into the space and from there into the drain pipe Hi.

If the valve It is displaced to the right out of the closed position shown, the passage l8 and with it the'spaces to the right of the pistons 46, 41 is connected to the pressure medium supply 15, while the pressure medium from the spaces to the left of the pistons 46, 47 passes by the route indicated to the passage il and through the longitudinal passage 1'! and the openings is to the space [ill and to the drain pipe l6. c

The lubricating oil supply or the oil filling of the hub of the adjustable propeller is provided through the stufiing-box M. The latter has a passage 1-9 which communicates with a lubricant tank arranged so high above the water level ofthe water craft that the hydrostatic pressure the hub slightly exceeds the greatest hydrostatic pressure outside the hub. In thestuffing-box M is a lubricating groove 80, inserted opposite the passage 19, and the passage 8! in the propeller shaft is arranged in the same cross-section, so that even when the shaft turns filling is always possible from the pipe 19. The passage '81- into the passage iii. of the adjusting member *48,

which is sealed olT from the servomotor I by a packing 83. The passage 82 extends through the whole of the propeller shaft 3 to the hub of the propeller. On the underside of the stufiing-box M are two drain passages 84, which conduct into the interior of the casing 6 any lubricating medium leaking through the packing M.

I claim:

1. For use in a controllable-pitch propeller assembly, a stationary casing, a shaft passing through said casing comprising a driving shaft portion, a driven hollow shaft portion and a tubular housing portion communicating internally with said driven hollow portion, all said shaft portions being connected in torque-transmitting relation to one another, a control linkage memberactivate said control linkage member, a stationary source of fluid under pressure located outside said shaft, a stationary sleeve surrounding said shaft, and passages contained in said shaft lead'-' ing from the interior of said housing portion to the exterior of said shaft within said sleeve, said sleeve serving to transmit 'fiuid under pres sure from said source to said servomotor through and spaced away from said packing elements.

In the combination of claim 1, fluid transmitti-ng means including annular grooves insidethe sleeve, conduits in the shaft leading from said grooves to the pressure-fluid chamber of the servomotor, tubes leading from the outer walls of said sleeve to the source of fluid under pressure, and the conduits in the body of said sleeve leading from said grooves to said tubes.

3. In the combination of claim 2, a control member for introducing selectively the fluid under pressure to chosen portions of the servomotor pressure-fluid chamber, said control member being located inside the casing and including a valve chamber inserted in the fluid transmitting means and an operable valve member within said valve chamber.

4. In the combination of claim 1, a sump within the casing for collecting fluid leading past the sleeve, a fluid pump scavenging from said sump, a fluid receiver outside said sleeve and tubes connecting said pump to said receiver.

5. In the combination of claim 1, means for relieving the shaft of at least a part of the weight of the casing, said means consisting of elastic elements connecting said casing to fixed points of support.

EDOUARD ATTESLANDER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name- Date 1,945,0'71 Popp Jan. 30, 1934 2,028,448 Harza Jan. 21, 1936 2,210,009 Ruths et a1 Aug. 6, 1940 2,244,770 Englesson June 10, 1941 2,456,361 Atteslander Dec. 14, 1948 FOREIGN PATENTS Number Country Date 553,929 Great Britain June 10, 1943 

